package cn.tedu.team.deml.filter;



import cn.tedu.team.deml.entity.User;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

@WebFilter(filterName = "MyFilter",urlPatterns = {"/insertProduct.html","/admin.html"})
public class MyFilter implements Filter {
    //当过滤器销毁时执行的方法
    public void destroy() {
    }
    //当接收到请求时会执行此方法,需要在此方法中进行判断 是否允许访问Controller或静态资源文件
    public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws ServletException, IOException {
        HttpServletRequest st = (HttpServletRequest) req;
        HttpServletResponse se = (HttpServletResponse) resp;
        //得到会话对象
        HttpSession session = st.getSession();
        //从会话对象中得到登录成功时保存的用户对象
        User user = (User) session.getAttribute("user");
        if (user!=null){//代表登录过
            chain.doFilter(req, resp);//放行 允许访问资源
        }else{//代表未登录
            se.sendRedirect("/login.html"); //重定向 让客户端重新向指定的地址发出请求
        }
        System.out.println("过滤器执行了");
    }
    //当过滤器初始化时执行的方法
    public void init(FilterConfig config) throws ServletException {

    }

}
